Megaliths are simply monuments built of large stones. In Southeast Asia and Oceania, a variety of megaliths are found, some thousands of years old, others brand new. Early studies of these structures viewed them primarily in the context of theories suggesting prehistoric migrations of megalith builders. In 1928 the eminent Austrian archaeologist Robert Heine-Geldern wrote the first of a series of influential articles, in which he argued that megaliths were created during two great waves of prehistoric migrations into Southeast Asia. The first group, the "Older Megalithic Culture," was thought to have ushered in the Neolithic age, while the second, the "Younger Megalithic Culture," was credited with the introduction of metal.

Heine-Geldern's view of megaliths as stepping-stones by which archaeologists could trace prehistoric migrations dominated Southeast Asian archaeology for many years, giving rise to extensive debates on the "problem of megaliths." In the past few decades, however...